10 Best Outdoor Tankless Water Heaters 2026 in the United States

The Rinnai RXP199iN is a highly efficient tankless water heater that can operate on either propane or natural gas, making it versatile in terms of energy source. With a flow rate of up to 11.1 gallons per minute (GPM), it can supply hot water for multiple fixtures simultaneously, which is great for larger households or outdoor uses where instant hot water is a necessity. Its BTU rating of 199,000 indicates strong heating performance.

The Rinnai RX199iN Condensing Smart Sense Tankless Water Heater is a solid choice for those seeking an efficient and high-capacity hot water solution for their home. With a flow rate of up to 11.1 gallons per minute (GPM), this heater can handle multiple fixtures simultaneously, making it ideal for larger households or homes with high hot water demand. Its 199,000 BTU rating ensures that it heats water quickly, maintaining a steady supply.

The Rinnai RX160iN is a versatile tankless water heater designed for both indoor and outdoor use, making it a flexible choice if you want installation options. It delivers up to 9 gallons per minute, enough to supply six fixtures at once, which should cover most household needs comfortably. Its high BTU rating of 160,000 means it can provide a strong temperature rise, keeping your water hot even in colder climates. The unit boasts an impressive energy efficiency rating (UEF 0.97), which helps save on energy bills over time. Installation requires a professional, especially for outdoor setups where the Versa Vent system and an outdoor vent cap are necessary for safe operation.